Alfa Romeo entered a supercharged 158, a well-developed pre-war design that debuted in 1938, and managed to win all six races they competed in.
Italian Giuseppe "Nino" Farina and Argentine teammate Juan Manuel Fangio both won three races and set three fastest laps.
The Alfa Romeo team dominated the British Grand Prix at the fast Silverstone circuit in England, locking out the four-car front row of the grid.
With King George VI in attendance, Giuseppe Farina won the race from pole position, also setting the fastest lap.
The podium was completed by his teammates Luigi Fagioli and Reg Parnell, while the remaining Alfa driver, Juan Manuel Fangio, was forced to retire after experiencing problems with his engine.
A first-lap accident caused by the damp track had eliminated nine of the nineteen starters—including Farina and Fagioli—while González, who had incurred damage in the pile-up, retired on the following lap.
[7] Alfa Romeo's dominance continued when the World Championship returned to Europe for the Swiss Grand Prix at the tree-lined Bremgarten circuit outside Bern.
Farina took the win and the fastest lap, finishing just ahead of Fagioli, while Rosier, in third place due to Fangio's retirement, took Talbot-Lago's first podium.
[9] Alfa Romeo was largely unchallenged at the French Grand Prix, held at the high-speed Reims-Gueux circuit, due to the withdrawal of the works Ferraris of Ascari and Villoresi.
The power of the Alfas suited this public road circuit- made up entirely of long straights, and Farina, starting from second, led for the first quarter of the race before fuel problems put him to the back of the field.
[10] The final championship round of the season was the Italian Grand Prix at the Monza Autodrome near Milan, and all three of the regular Alfa Romeo drivers were in contention for the title.
Fagioli's only chance of becoming World Champion was if he won the race and set the fastest lap; even then, he would need Farina to finish no higher than third, and Fangio would have to score no points at all.
Ascari took over Serafini's car and ultimately finished second behind Farina, whose victory clinched the title by taking him three points clear of Fangio.